I read it and didn't see a suggestion for if you don't have a slotted Al toe rail.
If you look at Rich Stidger's solution he attaches his to the gate ring. Your boat has a gate on each side, right? If your boat does not have gates you can also use a stanchion. Your boat has stanchions? If your boat has neither, then perhaps a gang plank is in order.
The step is a solution, how you attach it to your boat that does not have the traditional aluminum toe rail is for your ingenuity. Perhaps if we had some pics of what your boat looks like, some might offer suggestions for your consideration.